Priorly, when generating a speed pattern by a programmable controller, as shown in the block diagram of a controller of FIG. 4, in a speed pattern generator portion 42 which automatically generates an acceleration and deceleration pattern (such as a trapezoidal wave pattern, an asymmetric pattern and the like) based on a move command 41 (processing program) giving the amount of movement, speed, acceleration time, and deceleration time, for example, a trapezoidal wave acceleration and deceleration pattern is generated, a speed command 43 including the acceleration time, specified speed, deceleration time, amount of movement represented by the area of the trapezoid, as shown in FIG. 5, is output and provided for a servo control portion 44, and a servomotor 45 is controlled by the speed command.
Also, in a case of synchronous control between two spindles (the number of main and slave spindles is not specified) having the master-servant relationship where the slave spindle is driven in synchronization with movement of the main spindle as shown in FIG. 6, similar to the case of the speed command for one spindle (asynchronous control) as shown in FIG. 5, a speed command, which is provided for the main spindle and slave spindle, respectively, while maintaining the synchronous relationship, is automatically generated in accordance with a command from the superordinate.
However, in the above-described prior art, according to the speed pattern generating function, the move command (or a processing program) is analyzed, thereupon the speed pattern is automatically generated, therefore generation of the speed pattern has been fixed to synchronous/asynchronous timing specified by the move command and it has been impossible for a user to carry out a start/stop at free timing.
In addition, when the speed pattern is generated by the speed pattern generating function, the calculation results are directly output to the servomotor, therefore, it has been impossible to process said speed pattern halfway and output these to the servomotor as a speed command.
Accordingly, there has been a problem such that, due to the above-described drawbacks, speed patterns other than the speed pattern provided by the controller cannot be realized.
Therefore, it is an object of the present invention to provide a speed pattern generator as one function and open the calculation results to the user without outputting the results as a command to a servomotor, whereby providing a programmable controller which is capable of providing an environment which allows the user to realize an arbitrary speed pattern.